A pie marker is a portioning tool for cutting pies, cakes, and tarts into equal slices, typically a frame holding radial divider arms or a wheel-shaped blade that scores the top. In professional bakeries and catering, where dozens of identical portions must be produced quickly and fairly, the marker guarantees consistency that freehand cutting cannot: every slice the same size, every customer served equally. Adjustable models handle different slice counts for different products. Beyond portion control, even slices cook and present uniformly and simplify costing, since food cost per portion depends on accurate division. The tool exemplifies the unglamorous precision behind commercial baking: customers notice beautiful cakes, not the marker that ensured the eighth slice matched the first, but the business depends on both.